Valeria Sander - Academia.edu (original) (raw)
Papers by Valeria Sander
Frontiers in Veterinary Science, Mar 29, 2022
Memorias Do Instituto Oswaldo Cruz, Sep 1, 2006
We conducted a whole year research on the ecology of Mansonia indubitans and Ma. titillans in Mac... more We conducted a whole year research on the ecology of Mansonia indubitans and Ma. titillans in Macáes Pond,
Springer eBooks, 2018
Toxoplasmosis is a worldwide-distributed infection caused by Toxoplasma gondii, which causes a wi... more Toxoplasmosis is a worldwide-distributed infection caused by Toxoplasma gondii, which causes a wide range of clinical syndromes in humans, mammals and birds. T. gondii is considered a parasite of veterinary and medical importance, because it may cause abortion or congenital disease in its intermediate hosts. Despite the economic losses associated with T. gondii infection in farm animals and the socio-economic impact caused by this zoonotic disease in the human population, there is no effective treatment available for humans or animals able to eliminate the parasite from the host once the chronic infection has been established. The only commercial vaccine is the S48 strain of attenuated tachyzoites for use in sheep. However, this vaccine causes side effects, has a short life time and induces a short-term immunity. So far, no acellular vaccine against toxoplasmosis has been commercialized. In fact, future challenges include the development of an effective vaccine to prevent toxoplasmosis. Most parasitologists and vaccinologists agree that future efforts should be concentrated on developing multi-antigen vaccines and more efficient delivery systems able to express heterologous proteins abundantly as well as on searching for immunization schedules and adequate adjuvants to enhance the protective responses. To achieve this, platforms for the production of acellular vaccines based on the use of plants can have an important role.
Frontiers in Veterinary Science, Feb 12, 2019
Coccidial parasites cause medical and veterinary diseases worldwide, frequently leading to severe... more Coccidial parasites cause medical and veterinary diseases worldwide, frequently leading to severe illness and important economic losses. At present, drugs, chemotherapeutics and prophylactic vaccines are still missing for most of the coccidial infections. Moreover, the development and administration of drugs and chemotherapeutics against these diseases would not be adequate in livestock, since they may generate unacceptable residues in milk and meat that would avoid their commercialization. In this scenario, prophylactic vaccines emerge as the most suitable approach. Subunit vaccines have proven to be biologically safe and economically viable, allowing researchers to choose among the best antigens against each pathogen. However, they are generally poorly immunogenic and require the addition of adjuvant compounds to the vaccine formulation. During the last decades, research involving plant immunomodulatory compounds has become an important field of study based on their potential pharmaceutical applications. Some plant molecules such as saponins, polysaccharides, lectins and heat shock proteins are being explored as candidates for adjuvant/carriers formulations. Moreover, plant-derived immune stimulatory compounds open the possibility to attain the main goal in adjuvant research: a safe and non-toxic adjuvant capable of strongly boosting and directing immune responses that could be incorporated into different vaccine formulations, including mucosal vaccines. Here, we review the immunomodulatory properties of several plant molecules and discuss their application and future perspective as adjuvants in the development of vaccines against coccidial infections.
Plant Biotechnology Journal, Oct 1, 2012
The parasitic protozoan Toxoplasma gondii, the causal agent of toxoplasmosis, can infect most mam... more The parasitic protozoan Toxoplasma gondii, the causal agent of toxoplasmosis, can infect most mammals and birds. In human medicine, T. gondii can cause complications in pregnant women and immunodeficient individuals, while in veterinary medicine, T. gondii infection has economic importance due to abortion and neonatal loss in livestock. Thus, the development of an effective anti-Toxoplasma vaccine would be of great value. In this study, we analysed the expression of T. gondii GRA4 antigen by chloroplast transformation (chlGRA4) in tobacco plants and evaluated the humoral and cellular responses and the grade of protection after oral administration of chlGRA4 in a murine model. The Western blot analysis revealed a specific 34-kDa band mainly present in the insoluble fractions. The chlGRA4 accumulation levels were approximately 6 lg/g of fresh weight (equivalent to 0.2% of total protein). Oral immunization with chlGRA4 resulted in a decrease of 59% in the brain cyst load of mice compared to control mice. ChlGRA4 immunization elicited both a mucosal immune response characterized by the production of specific IgA, and IFN-c, IL-4 and IL-10 secretion by mesenteric lymph node cells, and a systemic response in terms of GRA4-specific serum antibodies and secretion of IFN-c, IL-4 and IL-10 by splenocytes. Our results indicate that oral administration of chlGRA4 promotes the elicitation of both mucosal and systemic balanced Th1/Th2 responses that control Toxoplasma infection, reducing parasite loads.
International Journal of Molecular Sciences, Mar 17, 2019
The serine protease inhibitors (SPIs) are widely distributed in living organisms like bacteria, f... more The serine protease inhibitors (SPIs) are widely distributed in living organisms like bacteria, fungi, plants, and humans. The main function of SPIs as protease enzymes is to regulate the proteolytic activity. In plants, most of the studies of SPIs have been focused on their physiological role. The initial studies carried out in plants showed that SPIs participate in the regulation of endogenous proteolytic processes, as the regulation of proteases in seeds. Besides, it was observed that SPIs also participate in the regulation of cell death during plant development and senescence. On the other hand, plant SPIs have an important role in plant defense against pests and phytopathogenic microorganisms. In the last 20 years, several transgenic plants over-expressing SPIs have been produced and tested in order to achieve the increase of the resistance against pathogenic insects. Finally, in molecular farming, SPIs have been employed to minimize the proteolysis of recombinant proteins expressed in plants. The present review discusses the potential biotechnological applications of plant SPIs in the agriculture field.
Reproduction, 2003
Corpus luteum regression has been described in terms of: (i) functional luteolysis - a reversible... more Corpus luteum regression has been described in terms of: (i) functional luteolysis - a reversible decline in serum progesterone concentration; and (ii) structural luteolysis - irreversible morphological changes and tissue remodelling events within the cellular membrane. In rats, PGF(2alpha) and interleukin 1beta (IL-1beta) are involved in structural luteolysis, PGF(2alpha) by increasing ovarian lipid peroxidation, and IL-1beta by reducing progesterone and increasing PGF(2alpha) concentrations. The aim of the present report was to determine whether by an early action IL-1beta is able to regulate functional luteolysis. Thus, ovarian explants from rats at the mid-stage of corpus luteum development were incubated during short periods with either 15 or 25 ng IL-1beta ml(-1). At 15 ng ml(-1), IL-1beta inhibited progesterone after 4 and 8 h of culture without affecting PGF(2alpha) production, and a longer incubation (21 h) was needed to increase PGF(2alpha) production. In contrast, IL-1bet...
The Journal of Steroid Biochemistry and Molecular Biology, Mar 1, 2011
The objective of the present study was to examine some factors involved in follicular development... more The objective of the present study was to examine some factors involved in follicular development of women with polycystic ovary syndrome (PCOS). Women with PCOS showed increased levels of serum luteinizing hormone (LH) but decreased follicular production of progesterone and estradiol by pre-ovulatory follicles. The mRNA expression corresponding to steroidogenic acute regulatory protein (StAR), and 20alpha-hydroxysteroid dehydrogenase (20␣-HSD) was increased, while that corresponding to cytochrome P450 aromatase (P450arom) was decreased in PCOS follicles as compared to controls. No changes in the mRNA expression for 3beta-hydroxysteroid dehydrogenase 2 (3-HSD2), cytochrome P450 side-chain cleavage (P450scc), cytochrome P450 17 alpha hydroxylase/lyase (P450c17), cyclooxygenase 2 (COX2), and transcription factors (GATA-4 and GATA-6) were found. We conclude that despite the hyper-luteinized environment of PCOS follicles, these follicles produce lower levels of progesterone and estradiol, and that this is characterized by increased degradation of progesterone and decreased estradiol synthesis. Our data demonstrate that the synthesis of prostaglandin F2␣ (PGF2␣) may be affected in PCOS-follicles and that the transcription factors GATA-4 and GATA-6 are present in PCOS-follicles but they are not involved in the abnormal transcription observed in the steroidogenic enzymes.
The Journal of Steroid Biochemistry and Molecular Biology, 2011
The objective of the present study was to examine some factors involved in follicular development... more The objective of the present study was to examine some factors involved in follicular development of women with polycystic ovary syndrome (PCOS). Women with PCOS showed increased levels of serum luteinizing hormone (LH) but decreased follicular production of progesterone and estradiol by pre-ovulatory follicles. The mRNA expression corresponding to steroidogenic acute regulatory protein (StAR), and 20alpha-hydroxysteroid dehydrogenase (20␣-HSD) was increased, while that corresponding to cytochrome P450 aromatase (P450arom) was decreased in PCOS follicles as compared to controls. No changes in the mRNA expression for 3beta-hydroxysteroid dehydrogenase 2 (3-HSD2), cytochrome P450 side-chain cleavage (P450scc), cytochrome P450 17 alpha hydroxylase/lyase (P450c17), cyclooxygenase 2 (COX2), and transcription factors (GATA-4 and GATA-6) were found. We conclude that despite the hyper-luteinized environment of PCOS follicles, these follicles produce lower levels of progesterone and estradiol, and that this is characterized by increased degradation of progesterone and decreased estradiol synthesis. Our data demonstrate that the synthesis of prostaglandin F2␣ (PGF2␣) may be affected in PCOS-follicles and that the transcription factors GATA-4 and GATA-6 are present in PCOS-follicles but they are not involved in the abnormal transcription observed in the steroidogenic enzymes.
Additional file 1: Figure S1. Immunoblot profiles of extract from tachyzoite lysate antigens (TLA... more Additional file 1: Figure S1. Immunoblot profiles of extract from tachyzoite lysate antigens (TLA) probed with sera (1:100) from PBS-immunized mice (Lane 1), NbHsp90-immunized mice (Lane 2), SAG1m-immunized mice (Lane 3), NbHsp90.3-SAG1HC-immunized mice (Lane 4) and with mouse anti-rSAG1m polyclonal antibody (1:1000) (C+). The arrow indicates the band that reacted with SAG1m- and NbHsp90.3-SAG1HC-positive sera and anti-rSAG1m polyclonal antibody. M: molecular weight marker (Fermentas).
Toxoplasmosis is a worldwide-distributed infection caused by Toxoplasma gondii, which causes a wi... more Toxoplasmosis is a worldwide-distributed infection caused by Toxoplasma gondii, which causes a wide range of clinical syndromes in humans, mammals and birds. T. gondii is considered a parasite of veterinary and medical importance, because it may cause abortion or congenital disease in its intermediate hosts. Despite the economic losses associated with T. gondii infection in farm animals and the socio-economic impact caused by this zoonotic disease in the human population, there is no effective treatment available for humans or animals able to eliminate the parasite from the host once the chronic infection has been established. The only commercial vaccine is the S48 strain of attenuated tachyzoites for use in sheep. However, this vaccine causes side effects, has a short life time and induces a short-term immunity. So far, no acellular vaccine against toxoplasmosis has been commercialized. In fact, future challenges include the development of an effective vaccine to prevent toxoplasmo...
Here, we evaluated the modulation of the immune response induced by Hsp90 of Nicotiana benthamian... more Here, we evaluated the modulation of the immune response induced by Hsp90 of Nicotiana benthamiana (NbHsp90.3) against the Maltose Binding Protein (MBP) as a reporter antigen. Equimolar quantities of recombinant proteins were administered in mice as follows: MBP alone (MBP group), a mixture of MBP and rNbHsp90.3 (MBP+rNbHsp90.3 group) and the fusion of MBP to rNbHsp90.3 (MBP-rNbHsp90.3 group). The covalent linkage between NbHsp90.3 and MBP to bring a fusion protein was essential to induce the strong specific antibody response with predominance of IgG2a. Eighty-four days after the first immunization, splenocyte proliferation from MBP-rNbHsp90.3-immunized mice was consistently higher than that from MBP and MBP+rNbHsp90.3 groups. In addition, splenocytes from MBP-rNbHsp90.3 immunized mice produced higher levels of IFN-γ than controls. Finally, both formulations with rNbHsp90.3 significantly enhanced the MHC class I expression levels, but only rNbHsp90.3 covalent bound to MBP induced a ...
Chloroplast transformation technology has emerged as an alternative platform offering many advant... more Chloroplast transformation technology has emerged as an alternative platform offering many advantages over nuclear transformation. SAG1 is the main surface antigen of the intracellular parasite Toxoplasma gondii and a promising candidate to produce an anti-T. gondii vaccine. The aim of this study was to investigate the expression of SAG1 using chloroplast transformation technology in tobacco plants. In order to improve expression in transplastomic plants, we also expressed the 90-kDa heat shock protein of Leishmania infantum (LiHsp83) as a carrier for the SAG1 antigen. SAG1 protein accumulation in transplastomic plants was approximately 0.1-0.2 μg per gram of fresh weight (FW). Fusion of SAG1 to LiHsp83 significantly increased the level of SAG1 accumulation in tobacco chloroplasts (by up to 500-fold). We also evaluated the functionality of the chLiHsp83-SAG1. Three human seropositive samples reacted with SAG1 expressed in transplastomic chLiHsp83-SAG1 plants. Oral immunization with ...
The endocrine and immune systems modulate ovarian function. The aim of the present work was to co... more The endocrine and immune systems modulate ovarian function. The aim of the present work was to compare the status of various modulating factors in two well-defined stages of corpus luteum (CL) development (the functional stage and the regressing stage) by means of a gonadotropin-synchronised mouse model. At the regressing stage of CL development, we found that ovarian tissue showed increased prostaglandin (PG) F(2alpha) and diminished PGE levels concomitantly with enhanced protein abundance of ovarian cyclooxygenase 2, the inducible isoform of the limiting enzyme of PG synthesis. We also found both enhanced lipid peroxidation and enhanced total superoxide dismutase activity, as well as inhibited catalase activity and inhibited total hydroxyl radical scavenger capacity, when compared with ovaries at the functional stage. In addition, at the regressing stage we observed an increased percentage of CD8+ (cytotoxic/suppressor) T-cells and a decreased percentage of CD4+ (helper) T-cells f...
The aim of the present report was to study the role of high levels of dehydroepiandrosterone (DHE... more The aim of the present report was to study the role of high levels of dehydroepiandrosterone (DHEA) on the ovarian function and embryonic resorption during early pregnancy in BALB/c mice. Pregnant animals were injected with DHEA following both the post-implantatory (DHEA-2) and peri-implantatory (DHEA-6) models. Morphological studies of implantation sites showed 40% of embryonic resorption in the DHEA-2 group while 100% of resorption was observed in the DHEA-6 group. Serum samples of both DHEA-2 and DHEA-6 groups showed higher estradiol levels and a lower progesterone concentration than those of control groups. Ovarian prostaglandin E levels after both DHEA-2 and DHEA-6 treatments increased when compared to control groups. The antioxidant metabolite glutathione diminished during both DHEA treatments. In summary, the data presented here suggest that DHEA treatment during early pregnancy modulates the ovarian function and is responsible for embryonic resorption with different degrees ...
An alteration in the balance of autocrine/paracrine ovarian factors may lead to different disease... more An alteration in the balance of autocrine/paracrine ovarian factors may lead to different diseases. The aim of the present report was to evaluate the relationship between insulin growth factor 1 (IGF-1) and leptin (Lp) in the progesterone (P) and estradiol (E) production after ovarian rat FSH stimulation. Thus, ovarian explants were incubated with FSH, IGF-1 and Lp, and P and E were evaluated by means of specific radioimmunoassays. FSH increased ovarian P and E production. IGF-1 synergized with FSH in P as well as in ovarian E production. Lp had not shown any effect on the FSH capacity to increase P and E in the ovarian tissue; nevertheless it reverted the synergistic effect of IGF-1 on FSH for P as well as for E. These data raise the possibility that abnormal Lp levels may contribute to infertility in women with polycystic ovarian syndrome by counteracting the sensitizing effects of IGF-1 in ovarian tissue.
Frontiers in Veterinary Science, Mar 29, 2022
Memorias Do Instituto Oswaldo Cruz, Sep 1, 2006
We conducted a whole year research on the ecology of Mansonia indubitans and Ma. titillans in Mac... more We conducted a whole year research on the ecology of Mansonia indubitans and Ma. titillans in Macáes Pond,
Springer eBooks, 2018
Toxoplasmosis is a worldwide-distributed infection caused by Toxoplasma gondii, which causes a wi... more Toxoplasmosis is a worldwide-distributed infection caused by Toxoplasma gondii, which causes a wide range of clinical syndromes in humans, mammals and birds. T. gondii is considered a parasite of veterinary and medical importance, because it may cause abortion or congenital disease in its intermediate hosts. Despite the economic losses associated with T. gondii infection in farm animals and the socio-economic impact caused by this zoonotic disease in the human population, there is no effective treatment available for humans or animals able to eliminate the parasite from the host once the chronic infection has been established. The only commercial vaccine is the S48 strain of attenuated tachyzoites for use in sheep. However, this vaccine causes side effects, has a short life time and induces a short-term immunity. So far, no acellular vaccine against toxoplasmosis has been commercialized. In fact, future challenges include the development of an effective vaccine to prevent toxoplasmosis. Most parasitologists and vaccinologists agree that future efforts should be concentrated on developing multi-antigen vaccines and more efficient delivery systems able to express heterologous proteins abundantly as well as on searching for immunization schedules and adequate adjuvants to enhance the protective responses. To achieve this, platforms for the production of acellular vaccines based on the use of plants can have an important role.
Frontiers in Veterinary Science, Feb 12, 2019
Coccidial parasites cause medical and veterinary diseases worldwide, frequently leading to severe... more Coccidial parasites cause medical and veterinary diseases worldwide, frequently leading to severe illness and important economic losses. At present, drugs, chemotherapeutics and prophylactic vaccines are still missing for most of the coccidial infections. Moreover, the development and administration of drugs and chemotherapeutics against these diseases would not be adequate in livestock, since they may generate unacceptable residues in milk and meat that would avoid their commercialization. In this scenario, prophylactic vaccines emerge as the most suitable approach. Subunit vaccines have proven to be biologically safe and economically viable, allowing researchers to choose among the best antigens against each pathogen. However, they are generally poorly immunogenic and require the addition of adjuvant compounds to the vaccine formulation. During the last decades, research involving plant immunomodulatory compounds has become an important field of study based on their potential pharmaceutical applications. Some plant molecules such as saponins, polysaccharides, lectins and heat shock proteins are being explored as candidates for adjuvant/carriers formulations. Moreover, plant-derived immune stimulatory compounds open the possibility to attain the main goal in adjuvant research: a safe and non-toxic adjuvant capable of strongly boosting and directing immune responses that could be incorporated into different vaccine formulations, including mucosal vaccines. Here, we review the immunomodulatory properties of several plant molecules and discuss their application and future perspective as adjuvants in the development of vaccines against coccidial infections.
Plant Biotechnology Journal, Oct 1, 2012
The parasitic protozoan Toxoplasma gondii, the causal agent of toxoplasmosis, can infect most mam... more The parasitic protozoan Toxoplasma gondii, the causal agent of toxoplasmosis, can infect most mammals and birds. In human medicine, T. gondii can cause complications in pregnant women and immunodeficient individuals, while in veterinary medicine, T. gondii infection has economic importance due to abortion and neonatal loss in livestock. Thus, the development of an effective anti-Toxoplasma vaccine would be of great value. In this study, we analysed the expression of T. gondii GRA4 antigen by chloroplast transformation (chlGRA4) in tobacco plants and evaluated the humoral and cellular responses and the grade of protection after oral administration of chlGRA4 in a murine model. The Western blot analysis revealed a specific 34-kDa band mainly present in the insoluble fractions. The chlGRA4 accumulation levels were approximately 6 lg/g of fresh weight (equivalent to 0.2% of total protein). Oral immunization with chlGRA4 resulted in a decrease of 59% in the brain cyst load of mice compared to control mice. ChlGRA4 immunization elicited both a mucosal immune response characterized by the production of specific IgA, and IFN-c, IL-4 and IL-10 secretion by mesenteric lymph node cells, and a systemic response in terms of GRA4-specific serum antibodies and secretion of IFN-c, IL-4 and IL-10 by splenocytes. Our results indicate that oral administration of chlGRA4 promotes the elicitation of both mucosal and systemic balanced Th1/Th2 responses that control Toxoplasma infection, reducing parasite loads.
International Journal of Molecular Sciences, Mar 17, 2019
The serine protease inhibitors (SPIs) are widely distributed in living organisms like bacteria, f... more The serine protease inhibitors (SPIs) are widely distributed in living organisms like bacteria, fungi, plants, and humans. The main function of SPIs as protease enzymes is to regulate the proteolytic activity. In plants, most of the studies of SPIs have been focused on their physiological role. The initial studies carried out in plants showed that SPIs participate in the regulation of endogenous proteolytic processes, as the regulation of proteases in seeds. Besides, it was observed that SPIs also participate in the regulation of cell death during plant development and senescence. On the other hand, plant SPIs have an important role in plant defense against pests and phytopathogenic microorganisms. In the last 20 years, several transgenic plants over-expressing SPIs have been produced and tested in order to achieve the increase of the resistance against pathogenic insects. Finally, in molecular farming, SPIs have been employed to minimize the proteolysis of recombinant proteins expressed in plants. The present review discusses the potential biotechnological applications of plant SPIs in the agriculture field.
Reproduction, 2003
Corpus luteum regression has been described in terms of: (i) functional luteolysis - a reversible... more Corpus luteum regression has been described in terms of: (i) functional luteolysis - a reversible decline in serum progesterone concentration; and (ii) structural luteolysis - irreversible morphological changes and tissue remodelling events within the cellular membrane. In rats, PGF(2alpha) and interleukin 1beta (IL-1beta) are involved in structural luteolysis, PGF(2alpha) by increasing ovarian lipid peroxidation, and IL-1beta by reducing progesterone and increasing PGF(2alpha) concentrations. The aim of the present report was to determine whether by an early action IL-1beta is able to regulate functional luteolysis. Thus, ovarian explants from rats at the mid-stage of corpus luteum development were incubated during short periods with either 15 or 25 ng IL-1beta ml(-1). At 15 ng ml(-1), IL-1beta inhibited progesterone after 4 and 8 h of culture without affecting PGF(2alpha) production, and a longer incubation (21 h) was needed to increase PGF(2alpha) production. In contrast, IL-1bet...
The Journal of Steroid Biochemistry and Molecular Biology, Mar 1, 2011
The objective of the present study was to examine some factors involved in follicular development... more The objective of the present study was to examine some factors involved in follicular development of women with polycystic ovary syndrome (PCOS). Women with PCOS showed increased levels of serum luteinizing hormone (LH) but decreased follicular production of progesterone and estradiol by pre-ovulatory follicles. The mRNA expression corresponding to steroidogenic acute regulatory protein (StAR), and 20alpha-hydroxysteroid dehydrogenase (20␣-HSD) was increased, while that corresponding to cytochrome P450 aromatase (P450arom) was decreased in PCOS follicles as compared to controls. No changes in the mRNA expression for 3beta-hydroxysteroid dehydrogenase 2 (3-HSD2), cytochrome P450 side-chain cleavage (P450scc), cytochrome P450 17 alpha hydroxylase/lyase (P450c17), cyclooxygenase 2 (COX2), and transcription factors (GATA-4 and GATA-6) were found. We conclude that despite the hyper-luteinized environment of PCOS follicles, these follicles produce lower levels of progesterone and estradiol, and that this is characterized by increased degradation of progesterone and decreased estradiol synthesis. Our data demonstrate that the synthesis of prostaglandin F2␣ (PGF2␣) may be affected in PCOS-follicles and that the transcription factors GATA-4 and GATA-6 are present in PCOS-follicles but they are not involved in the abnormal transcription observed in the steroidogenic enzymes.
The Journal of Steroid Biochemistry and Molecular Biology, 2011
The objective of the present study was to examine some factors involved in follicular development... more The objective of the present study was to examine some factors involved in follicular development of women with polycystic ovary syndrome (PCOS). Women with PCOS showed increased levels of serum luteinizing hormone (LH) but decreased follicular production of progesterone and estradiol by pre-ovulatory follicles. The mRNA expression corresponding to steroidogenic acute regulatory protein (StAR), and 20alpha-hydroxysteroid dehydrogenase (20␣-HSD) was increased, while that corresponding to cytochrome P450 aromatase (P450arom) was decreased in PCOS follicles as compared to controls. No changes in the mRNA expression for 3beta-hydroxysteroid dehydrogenase 2 (3-HSD2), cytochrome P450 side-chain cleavage (P450scc), cytochrome P450 17 alpha hydroxylase/lyase (P450c17), cyclooxygenase 2 (COX2), and transcription factors (GATA-4 and GATA-6) were found. We conclude that despite the hyper-luteinized environment of PCOS follicles, these follicles produce lower levels of progesterone and estradiol, and that this is characterized by increased degradation of progesterone and decreased estradiol synthesis. Our data demonstrate that the synthesis of prostaglandin F2␣ (PGF2␣) may be affected in PCOS-follicles and that the transcription factors GATA-4 and GATA-6 are present in PCOS-follicles but they are not involved in the abnormal transcription observed in the steroidogenic enzymes.
Additional file 1: Figure S1. Immunoblot profiles of extract from tachyzoite lysate antigens (TLA... more Additional file 1: Figure S1. Immunoblot profiles of extract from tachyzoite lysate antigens (TLA) probed with sera (1:100) from PBS-immunized mice (Lane 1), NbHsp90-immunized mice (Lane 2), SAG1m-immunized mice (Lane 3), NbHsp90.3-SAG1HC-immunized mice (Lane 4) and with mouse anti-rSAG1m polyclonal antibody (1:1000) (C+). The arrow indicates the band that reacted with SAG1m- and NbHsp90.3-SAG1HC-positive sera and anti-rSAG1m polyclonal antibody. M: molecular weight marker (Fermentas).
Toxoplasmosis is a worldwide-distributed infection caused by Toxoplasma gondii, which causes a wi... more Toxoplasmosis is a worldwide-distributed infection caused by Toxoplasma gondii, which causes a wide range of clinical syndromes in humans, mammals and birds. T. gondii is considered a parasite of veterinary and medical importance, because it may cause abortion or congenital disease in its intermediate hosts. Despite the economic losses associated with T. gondii infection in farm animals and the socio-economic impact caused by this zoonotic disease in the human population, there is no effective treatment available for humans or animals able to eliminate the parasite from the host once the chronic infection has been established. The only commercial vaccine is the S48 strain of attenuated tachyzoites for use in sheep. However, this vaccine causes side effects, has a short life time and induces a short-term immunity. So far, no acellular vaccine against toxoplasmosis has been commercialized. In fact, future challenges include the development of an effective vaccine to prevent toxoplasmo...
Here, we evaluated the modulation of the immune response induced by Hsp90 of Nicotiana benthamian... more Here, we evaluated the modulation of the immune response induced by Hsp90 of Nicotiana benthamiana (NbHsp90.3) against the Maltose Binding Protein (MBP) as a reporter antigen. Equimolar quantities of recombinant proteins were administered in mice as follows: MBP alone (MBP group), a mixture of MBP and rNbHsp90.3 (MBP+rNbHsp90.3 group) and the fusion of MBP to rNbHsp90.3 (MBP-rNbHsp90.3 group). The covalent linkage between NbHsp90.3 and MBP to bring a fusion protein was essential to induce the strong specific antibody response with predominance of IgG2a. Eighty-four days after the first immunization, splenocyte proliferation from MBP-rNbHsp90.3-immunized mice was consistently higher than that from MBP and MBP+rNbHsp90.3 groups. In addition, splenocytes from MBP-rNbHsp90.3 immunized mice produced higher levels of IFN-γ than controls. Finally, both formulations with rNbHsp90.3 significantly enhanced the MHC class I expression levels, but only rNbHsp90.3 covalent bound to MBP induced a ...
Chloroplast transformation technology has emerged as an alternative platform offering many advant... more Chloroplast transformation technology has emerged as an alternative platform offering many advantages over nuclear transformation. SAG1 is the main surface antigen of the intracellular parasite Toxoplasma gondii and a promising candidate to produce an anti-T. gondii vaccine. The aim of this study was to investigate the expression of SAG1 using chloroplast transformation technology in tobacco plants. In order to improve expression in transplastomic plants, we also expressed the 90-kDa heat shock protein of Leishmania infantum (LiHsp83) as a carrier for the SAG1 antigen. SAG1 protein accumulation in transplastomic plants was approximately 0.1-0.2 μg per gram of fresh weight (FW). Fusion of SAG1 to LiHsp83 significantly increased the level of SAG1 accumulation in tobacco chloroplasts (by up to 500-fold). We also evaluated the functionality of the chLiHsp83-SAG1. Three human seropositive samples reacted with SAG1 expressed in transplastomic chLiHsp83-SAG1 plants. Oral immunization with ...
The endocrine and immune systems modulate ovarian function. The aim of the present work was to co... more The endocrine and immune systems modulate ovarian function. The aim of the present work was to compare the status of various modulating factors in two well-defined stages of corpus luteum (CL) development (the functional stage and the regressing stage) by means of a gonadotropin-synchronised mouse model. At the regressing stage of CL development, we found that ovarian tissue showed increased prostaglandin (PG) F(2alpha) and diminished PGE levels concomitantly with enhanced protein abundance of ovarian cyclooxygenase 2, the inducible isoform of the limiting enzyme of PG synthesis. We also found both enhanced lipid peroxidation and enhanced total superoxide dismutase activity, as well as inhibited catalase activity and inhibited total hydroxyl radical scavenger capacity, when compared with ovaries at the functional stage. In addition, at the regressing stage we observed an increased percentage of CD8+ (cytotoxic/suppressor) T-cells and a decreased percentage of CD4+ (helper) T-cells f...
The aim of the present report was to study the role of high levels of dehydroepiandrosterone (DHE... more The aim of the present report was to study the role of high levels of dehydroepiandrosterone (DHEA) on the ovarian function and embryonic resorption during early pregnancy in BALB/c mice. Pregnant animals were injected with DHEA following both the post-implantatory (DHEA-2) and peri-implantatory (DHEA-6) models. Morphological studies of implantation sites showed 40% of embryonic resorption in the DHEA-2 group while 100% of resorption was observed in the DHEA-6 group. Serum samples of both DHEA-2 and DHEA-6 groups showed higher estradiol levels and a lower progesterone concentration than those of control groups. Ovarian prostaglandin E levels after both DHEA-2 and DHEA-6 treatments increased when compared to control groups. The antioxidant metabolite glutathione diminished during both DHEA treatments. In summary, the data presented here suggest that DHEA treatment during early pregnancy modulates the ovarian function and is responsible for embryonic resorption with different degrees ...
An alteration in the balance of autocrine/paracrine ovarian factors may lead to different disease... more An alteration in the balance of autocrine/paracrine ovarian factors may lead to different diseases. The aim of the present report was to evaluate the relationship between insulin growth factor 1 (IGF-1) and leptin (Lp) in the progesterone (P) and estradiol (E) production after ovarian rat FSH stimulation. Thus, ovarian explants were incubated with FSH, IGF-1 and Lp, and P and E were evaluated by means of specific radioimmunoassays. FSH increased ovarian P and E production. IGF-1 synergized with FSH in P as well as in ovarian E production. Lp had not shown any effect on the FSH capacity to increase P and E in the ovarian tissue; nevertheless it reverted the synergistic effect of IGF-1 on FSH for P as well as for E. These data raise the possibility that abnormal Lp levels may contribute to infertility in women with polycystic ovarian syndrome by counteracting the sensitizing effects of IGF-1 in ovarian tissue.